.formContainer{
    position: fixed;
    background-color: rgba(0,0,0,0.5);
    width: 500px;
    height: 300px;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
    /* 移至中间 */
    padding: 20px 50px;
    border-radius: 10px;
    z-index: 10;
}
.logintitle{
    text-align: center;
    height: 80px;
    line-height: 80px;
    font-size: 30px;
    color:white;
}
.login-form-button{
    left: 40%;
}